Work table for skiving machines



Feb. 11, 1958 E H. BECK WORK TABLE FOR SKIVING MACHINES Filed May 51,1957 WORK TABLE FOR SKlVlNG MACHINES Edwin H, Beck, Lemay, Mo., assignorto Manufacturers Supplies Co., St. Louis, Mo., a corporation of MissouriApplication May 31, 1957, Serial No. 662,926

2 Claims. c1. 9 -9.5

This invention relates to leather skiving machines, and moreparticularly to machines of the type having a bell type of cylindriccutter.

It will be understood that such a skiving machine generally comprises abase or housing containing a cup-like cutting knife, which is formedwith a back and a cylindric cutting portion projecting from the back,the end portion of the cylinder being ground to a bevel cutting edge.The knife rotatably is mounted by its back on a horizontal axis so thatonly a slight segment of the cylinder projects above the top of thehousing, there being an opening in the topof the housing for thispurpose. Usually, a feed roller is mounted beneath the cutting edge anda presser foot above the feeder in order to feed the leather against therotating edge of the knife. The machine is also provided with aknife-sharpening device within the housing so that the cutting edge canbe ground from time to time. After grinding, the knife is readjustedtoward the feeder, hence an increasingly large gap is opened at the backof the knife through the opening in the housing. In order to preventsmall pieces of work from falling into this gap, it has been proposedthat a shield be fixed to the housing so'as to extend over the knifesubstantially to its cutting edge. The disadvantage with such a shieldis it creates a bulge over the knife, whichinterferes with the movementofthe work as it leaves the feeder. Also, small particles sometimes tendto accumulate between the cylindric portion of the knife and theoverlying shield and develop a braking action on the cutter.

Accordingly, an object of this invention is to provide improved meansfor closing the gap in the housing at the back of the knife, whileleaving the knife relatively unobstructed so that the work may flow overit with a minimum of interference. Another object of the invention is toprovide a convenient attachment for the above purpose, which attachmentis also adapted to receive a work table extension so that the flat areaadjacent the knife can be conveniently enlarged. This is advantageousbecause it is often necessary to swing a relatively large piece ofleather about a vertical axis at the presser foot, as when skivingcurved edges.

Various other objects of the invention will be apparent in the detaileddescription, but briefly, I provide a cover plate, which is securedagainst the front wall of the housing so as to extend over the topsurface thereof. The top portion of the plate has a large recess formedto accommodate the knife where it projects upwardly from the housing,and the portion of the plate behind the knife carries a sliding guard,which is movable toward and away from the back of the knife.

As the cylindric portion of the knife is shortened by grinding, theknife is readjusted toward the feeder, and the sliding guard is alsomoved forwardly against the back portion of the knife in order to closethe gap that would otherwise occur. A simple friction fit between theguard and cover plate will normally be sufiicient to hold it in positionbut the guard may be readily opened to afford access to the space behindthe knife.

2,822,681 Pa en ed Fe 19.5.8

In addition, the invention contemplates the provision.

of a table-extension which is adapted'to'be secured to the front portionof the cover plate by a depending support and which otherwise projectshorizontally with respect to the work table from the front of themachine. The edges of the cover plate and work table extension areadapted to fit closely with one another so as to assure a smoothuninterrupted surface. Also, the depending support for the table mayhave a pin-and-hole'interlocking cooperation with the depending portionof the cover plate", thereby to lock the work table in proper position.With this arrangement, it is a relatively simple step to provide aseries of work table extensions to fit varying require: ments of thejob.

Other features of the invention will be in part apparent from and inpart pointed out in the following detailed description taken inconnection with the accompanying drawings, in which: i 1

Fig. l is an oblique view of a portion of a skiving machine illustratingthe knife-gap closure accessory of this invention;

Fig. 2 is a vertical section taken generally on the line 22 of Fig. 1; i

Fig. 3 is another vertical section taken generally on the line 33 ofFig. 1 but further showing'the work table extension; and

Fig. 4 is a top plan view, parts being broken away, showing the coverplate and work table extension in assembly.

Referring to Fig. 1 of the drawings, there is shown a portion of askiving machine of the type having a so-called bell knife. Such amachine includes a base housing ,1 containing certain mechanism (thedetails of whicharef not significant to this invention). A knifegenerally designated 3 is mounted within the housing and is'adapted tobe rotated about a horizontal axis by a suitable power uni-t. The knifeis formed with a back wall 5 so that it can be secured to a horizontalshaft, which is also adapted to permit axial adjustment of the knife.The cylindric portion 7 of the knife projects from the back toward afeed roller partially shown at 9. The feed roller is rotary about ahorizontal axis transverse to that of the knife so as to feed workagainst the cutting edge 11.

A typical skiving machine generally includes the grinding device (notshown) within the housing, which can be actuated by the operator fromtime to time so as to maintain a keen edge on the knife. The workotherwise is guided against the knife by a presser foot 13 adjustablycarried upon an arm 15, which projects upwardly and is supported fromthe back of the housing.

The work is guided under the presser foot from the left side as viewedin Fig. 1, whereupon the feed roller feeds the work against the cuttingedge. The presser foot may be at an angle to the knife in order toprovide a beveled skive along an edge of the work, which edge of thework moves from left to right as viewed in Fig. 1. In other words, afterbeing skived, the work moves over the top cylindric portion 7 of theknife and across the top of the housing. It will be apparent that aportion of the knife projects upwardly through an opening in thehousing, and as the knife edge is ground away from time to time, theentire knife is advanced toward the feeder so that the cutting edge willalways be adjacent the feed roller 9. This axial adjustment of theknife, in turn,

results in an increasingly large gap at its back 5, which is undesirablein certain classes of work since the small pieces could fall into thehousing.

In order to overcome this disadvantage, I provide a knife closureaccessory generally designated 17. A cover plate is curved to provide adepending portion 19 for fastening against the front of the housing 1and a portion 21 extending over the top of the housing. The dependingportion 19 has a pair of slots 21 receiving knurled screws 23. The topportion 21 of the plate is cut with a large recess 25 which surroundsthe knife and permits it to project upwardly 'as illustrated. In otherwords, the cylindric portion 7 of the knife is exposed at the top, hencethe cover plate does not interfere with movement of the work. The backedge of the slot 25 is sufiicient to accommodate the knife in its newcondition of maximum length, but asthe knife is worn down and movedforwardly, a gap will be opened.

' This gap is adapted to be closed, however, by a sliding guard 27,which has beveled edges 29 received within overhanging or dovetailguides 31 at opposite sides of the guard. The edge 33 of the guardadjacent the knife is suitably shaped to conform with the knife tosubstantially close any gap. Also, a finger notch 35 is provided in theguard to facilitate its adjustments toward and away from the knife. Inuse, the guard is adjusted after each adjustment of the knife, but ifdesired, the guard may be drawn back to afford access with the spaceadjacent the knife.

Referring now to Figs. 3 and 4, there is shown an extension whichcooperates with the knife guard device 13. This extension deviceincludes a fiat table portion 41 having an inner edge 43 conformed tofit closely with the upper flat portion 21 of the guard assembly. Thetable 41 is secured by a depending support 45, which is fastened againstthe depending portion 19 of the above cover plate. For example, theportion 19 may be provided with a pair of small pin holes 47 whichreceive aligning pins 49 secured to the support 45 of the work table. Aknurled screw 51 is then received through an opening in the tablesupport 45 and is threaded into a tapped hole 53 in the cover plate.With this arrangement, it is contemplated that there will be anassortment of table sizes in order to provide for various needs ofusers.

It will be understood, for example, that some relatively large pieces ofleather may have complicated curved edges which must be beveled orskived and since the edges of the work should move at right angles tothe edge 11 of the knife, it may be necessary to rotate or pivot workabout a vertical axis at the presser foot as it is moved therebeneath.With present skiving machines, the working area is rather small orsubstantially non-existent,

hence the skiving of such large pieces is often difficult.

' On the other hand, the provision of a table extension affords a largearea and clearly simplifies this type of operation.

From the foregoing description, it is apparent that those skilled in theart will understand the structure, function and mode of operation of theinvention herein disclosed, and appreciate the advantages thereof.Although one embodiment has been disclosed in detail, it is to beunderstood that the invention is not limited thereto, but the drawingsand description thereof are to be understood as being merelyillustrative. It is realized that many modifications and variations willpresent themselves to those skilled in the art without departing fromthe spirit of this invention or the scope thereof as set forth in theappended claims.

Having thus described the invention, what is claimed and desired to besecured by Letters Patent is:

l. A work table device for the bell knife of a leather skiving machineof the type described, comprising a cover plate having a top portionadapted to overlie the work table adjacent said knife and a dependingportion adapted to be secured against the front of the housing, and aguard plate slidably mounted on said top portion of the cover plate formovement toward and away from the knife thereby to close a gap adjacentthe knife.

2. In a skiving machine of the character described, having a housing, abell-type of knife projecting partially through an opening in the top ofthe housing, the knife having a cylindric surface which is shortened inuse and which is adjustably moved from time to time, thereby to open anincreasingly large gap through the housing adjacent the knife; theimprovement comprising a cover plate having a top surface overlying thehousing of the machine and recessed to accommodate the knife, said coverplate having a portion depending over and secured to the front of thehousing, and a guard member slidably mounted on the top of the coverplate for sliding movement over said opening toward and away from theknife, thereby to permit closure of the gap as the knife is shortened inuse.

Woodcock et a1 Nov. 25, 1930 Ray July 29, 1941

